A known vehicle with an on-board battery as a power source, such as a hybrid vehicle and an electric vehicle, has a battery temperature control system that control a temperature of the on-board battery (battery pack) by blowing air to the battery. The air blown to the battery needs to be cooled down and exhausted. For such a purpose, an exhaust duct is provided in a luggage compartment of the vehicle. The exhaust duct extends from the luggage compartment to the outside and thus the exhaust air from the battery is discharged to the outside of the vehicle.
One example of such vehicles is described in Japanese published patent application No. 2010-149647.
The configuration with which the exhaust air from the battery is discharged to the outside of the vehicle may require a long exhaust duct. If the exhaust duct is long, the exhaust duct takes up a large part of space in the luggage compartment and thus a size of usable space in the luggage compartment decreases. This is not desirable. A configuration in which space between assembly parts of the luggage compartment (e.g., an underfloor storage box and a vehicle body is configured as a part of an exhaust path (instead of an exhaust duct) to reduce a length of the exhaust duct.
If the space between assembly parts of the luggage compartment is used as a part of the exhaust path, the airtightness of the exhaust path is low in comparison to an exhaust duct. Exhaust gas may leak from an unexpected part of the exhaust path such as space between assembly parts.
The leaking exhaust gas may make occupants of the vehicle uncomfortable. For example, cool air may be forced into the occupant side by the leaking exhaust gas and the occupants feel uncomfortable with the cool air. If a spare tire in the luggage compartment of the vehicle is exposed to the exhaust gas, the occupants may feel uncomfortable due to the smell of the spare tire.